Compounds capable of hole and electron conduction and efficient energy transfer are ideally suited for use in a wide variety of applications, including optical and electro-optical devices, and photo-absorbing devices. Much research has been devoted to the discovery and optimization of organic and organometallic materials for use in such applications. Generally, research in this area aims to accomplish a number of goals, including improvements in hole and electron transport and energy level tuning, as well as improvements in processing ability, among others.
Despite significant advances in research devoted to optical and electro-optical materials, existing host materials have a number disadvantages, including poor processing ability, poor energy matching to certain emissive materials, poor charge carrier mobility, among others. Thus, a need exists for new materials which exhibit improved performance. This need and other needs are satisfied by the present invention.
Cyclometalated metal complexes can be used for many applications including host materials and emitters for OLEDs. One of most important factors dictating the quantum efficiency of emission, is proportional to the integral of wavefunction of ground state and excited state, which favors a small difference in their equilibrium geometry.
Despite significant advances in research devoted to optical, electro-optical, and marker materials, existing materials have a number disadvantages, including poor processing ability, inefficient emission or absorption, and less than ideal stability, among others. Thus, a need exists for new materials which exhibit improved performance in optical emitting and absorbing applications. This need and other needs are satisfied by the present invention.